Changes in Mangrove Cover and Exposure to Coastal Hazards in Kenya
Round 1
Reviewer 1 Report
Comments for the Manuscript Land 1922005
Title : Changes in Mangrove Cover and Exposure to Coastal Hazards in Kenya
The paper submitted by the authors are dealing with change in mangrove cover and exposure to coastal hazards in Kenya.
1. Similarities : An in-depth reading of the documents show that the topic is subject to many publications on various Journal Such as :
Chiara Ambrosino, Ben Hufton, Benson Okinyi Nyawade,Harriet Osimbo, and Phanuel Owiti ( 2021) Integrating Climate Adaptation, Poverty Reduction, and Environmental Conservation in Kwale County, Kenya (A chapter) https://link.springer.com › chapter
J. O. Bosire, J. J. Kaino, A. O. Olagoke, L. M. Mwihaki, G. M. Ogendi, J. G. Kairo, U. Berger, and D. Macharia (2014) Mangroves in peril: unprecedented degradation rates of peri-urban mangroves in Kenya. Biogeosciences, 11, 2623–2634, 2014
Caridad Ballesteros & Luciana S. Esteves (2021) Integrated Assessment of Coastal Exposure and Social Vulnerability to Coastal Hazards in East Africa Estuaries and Coasts (2021) 44:2056–2072
There are many similarities between table 1, p 5 of the presents paper with table 2 page 2059 of Ballesteros and Esteeves (2021). The authors need to explain why such a similarity which is not far from plagiarism, because the reference is not provide for this table.
The same with Figure 2 page 6 on Kenya and Tana River with Table 4 Page 2062 of Ballesteros and Esteeves (2021).
Ambrosino et al (2021) deal specifically with Kwale County. It means that most of counties choosen by the authors have been studied. It is necessary for the authors to make a fine contribution.
Looking at figure 4 (page 7), it seems that the authors took the scenarios provided by of Ballesteros and Esteeves (2021) at pages 2060-2061 and convert it into figure.
2. I could not understand the Figure 3, p6 if compare with the location map (figure 1) of page 3. There is something wrong on the way the map is draw. it seems to be a double coast! I can’t watch exposure and I wonder myself if it is not better for the authors to provide two maps.
3. Methods and Model used are not clear (Line 118-172). Global Mangrove Watch (GMW) data used are not explicated if we take the spatial resolution. We have not seen the sketch of image processing and could not understand the figure three dealing with exposure. Methods need to be rewritten with all equation linked to. Also InVEST model run choose is not well explained . It is similar to what Ballesteros and Esteeves (2021) used in page 2061. I wonder myself how the authors of the present paper assessed the coastal change vulnerability and exposure of their counties? Do the authors read InVEST model documentation to understand it use and limitations?
4. Conclusion: it seems that investigations on this topic is lacking and I do not understand how the authors could provide the presents results without giving any idea of the resolution of the adat used even though if they put emphasis in limitations section on : ‘The inconsistencies of global land cover data for local studies and are the use of different remote sensing devices, or different methods of image classification.
The authors need carefully to check their paper and conceived it in order to provide a good scientific soundness because there are so many publications on the topic in kenya.
Comments for author File: 
Comments.pdf
Author Response
Dear reviewer, thank you for your comments. We tried to address them as much as possible - we expanded on the Table 1 in our paper to explain how it was created, we added the information on spatial resolution of the GMW dataset. We also added the information from Ambrosino et al. (2021)chapter and referenced it - it contained some really useful information and we thank you for the suggestion. As per your suggestion, we have also redesigned the map.
Some of the issues you highlight as potential plagiarism from Ballesteros and Esteves (2021) are down to how the InVEST model software is set. A lot of parameters are intrinsic to the model, and every paper which uses this model will for example have the same scenarios (with and without habitats). Wherever possible, we tried to explain this to avoid the confusion.
We also believe our papers brings in novel data, despite the fact that mangroves have been studied in Kenya previously. We have identified differences in mangrove change between all counties using the same method and same data source consistently, and we further identified areas of highest concern for coastal vulnerability (through InVEST model) and mapped mangrove change in and around these areas.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Here is some advise to improve the content;
L 45. May be the following recent global synthesis is relevant for this line
Billah, M. M., Bhuiyan, M. K. A., Amran, M. I. U. A., Cabral, A. C., & Garcia, M. R. D. (2022). Polycyclic aromatic hydrocarbons (PAHs) pollution in mangrove ecosystems: global synthesis and future research directions. Reviews in Environmental Science and Bio/Technology, 1-24.
L85. Please give some idea of the previous work carried out on the similar aspects? What are previous findings on the degradations of Kenyan mangrove due to land reclamation/sea level rise
L100. Study site: although some climatic variables of the study site is presented, but there is no information of the ecology of mangroves (e.g., number of reported mangrove species, which species are generally abundant, fauna etc).
L254-255: “Past studies have identified overharvesting being the cause of changes in most counties in Kenya”-consider discussing more on this degradation factors
L 257: Here you should probably presents some point how these losses of mangroves in the Lamu county happened.
L 267: So here it is better to discuss what tis the current status of mangrove afforestation/restoration status in Kenya to tackle these massive degradations of mangrove forest.?
L311: But this paper did not explicitly shows implications of the mangrove degradations on the ecosystem functions?? please add some discussion related to this implications (e.g., fisheries reductions, or may be recreational loss etc)
Author Response
Dear reviewer, thank you for your comments and suggestions - we tried to tackle most of them, but some with limited success. For example, there isn't a lot of research on drivers of mangrove cover change in locations specific to our paper, as most research identified only areas of change at best, without focusing on the drivers of change. Therefore we tried to keep this part of the discussion a bit more general, while adding new references when possible. We also expanded on some other points you have risen in your review.
Author Response File: Author Response.docx
Reviewer 3 Report
The article is basically fine as is since it presents the results of the study clearly and acknowledges limitations and does not try to address Kenya’s overall coastal hazards issues and options or engage in any kind of critique or modification of the InVEST model. The following suggestions are mainly aimed at clarifying the authors’ understanding / meaning about vulnerability assessment, the context/ situation of mangrove conservation in Kenya, and the overall coastal hazards management approach in Kenya.
I recognize that there is no standard way to talk about coastal vulnerability, but I think it would be useful for the authors to be more clear and careful in identifying whether the article is mainly about mangrove forest change and loss or coastal hazards management. If the focus is mainly on mangroves, then the factors stressing the forests in different areas of the coast should be more clearly described (urbanization, deforestation for wood,charcoal, changes in salinity due to hydrological factors, other climate or watershed factors). The authors should also try harder to find examples of conservation and management (there are a number of funded community based projects in Kenya and national programs) as well as in adjacent East Africa countries rather than looking far afield to Indonesia or other very different contexts.
If the focus is on coastal hazard mitigation, and mangroves are seen as a way to reduce vulnerability of shorelines, coastal settlements and ecosystems, the basic concepts of vulnerability and mitigation need to be clear. Unfortunately I don’t have specific knowledge of the InVEST model—its logic may be different than the following points, so the authors are stuck with its approach. To me coastal vulnerability is a function of stressors that are or will be present in Kenya, the amount of exposure of natural resources or human assets/ settlements to these stressors in a given reach of the coast, the sensitivity of those resources/ assets to the stressors, and the adaptive capacity of nature and Kenyan society/economy/governance to respond. Mangroves have a degree of adaptive capacity to sea level rise if there are areas behind the existing forest areas where the plants can establish themselves. Kenyan coastal settlements might have adaptive capacity if they have good local governance and have been able to attract and sustain conservation efforts to protect the mangroves, resist the coastal stresses or retreat to safer areas.
I find it hard to follow the discussion starting on line 195 and Figure 4 by the use of exposure as a positive thing, when in fact Kenya needs to reduce the exposure of its shore and settlements to the coastal hazard stressors. It becomes unclear in the presentation of scenarios which are really occurring versus hypothetical. Lines 232-236 continue this confusion. Kenya needs to reduce its vulnerability to coastal hazards, and mangroves /corals help accomplish this to the extent they are allowed to exist and flourish, in conjunction with other adaptation measures.
The last paragraph on page 8 adds to the muddle by presenting new data about loss rates and comparing them to Indonesia for some reason. It doesn’t matter whether Kenya has different rates of loss than Tanzania or Indonesia, if the focus of the article in insuring the continuing contribution of mangroves and corals to coastal area resiliency and low vulnerability. It would be better if the authors could add some local examples from Kenya that explain loss/gain patterns in different parts of the coast.
Author Response
Dear reviewer, thank you for the comments and suggestions. We tried to take into consideration most of them, and we added paragraphs in the discussion section expanding on the issues of community based projects in Kenya as well as drivers of mangrove degradation in the country. You are also right when noticing that parts of the coastal vulnerability are basically down to how InVEST is set up - most of the constraints you mention are indeed due to the model and we are "stuck" with some of its parameters.
We have also rewritten some of the paragraphs you highlighted to avoid potential confusion about the benefits/damage mangrove loss might create.
Author Response File: Author Response.docx
Reviewer 4 Report
Suggestion to your interesting paper, but if it possible you can contrast the results and discussion with IPCC Grop 1, Sixth Assessment Report (AR6W1). Its provides projections to sea level and its uncertaly (IPCC, 2021). In order to provide a probabilistic explanation of the relationship mangroves and sea level rise according to the IPCC.
Author Response
Dear reviewer, thank you for the comment. We have expanded a part of our discussion and included a reference referring to the report you suggested.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Line 193 figures 3: Location on high and very high exposure areas on the Kenyan coast is now clear
Line 254, please just provide the some names of those areas and mainly african areas or tropical
Lines 285-286 there are restoration effort in some African countries
Line 318: when writing, if you numbered a title 4.1 it means that the reader is waiting for 4.2. Instead of that you neither to remove 4.1 or split the discussion section in two or three short paragraphs
Line 332: I don’t thing so, it seems that there are many studies in Africa lying on mangroves. You can see example on Great marine ecosystem of the world which encompasses 66 areas with particular emphasis on eastern, southern and western AfricaLine 336. I think it is necessary in conclusion to write some words on methodology before giving the finding. Also a single phrase on the limitations at the end of the conclusion is welcome
Author Response
Please see attachment. We appreciate all the suggestions.
Author Response File: Author Response.docx
Reviewer 2 Report
The paper can be accepted
Author Response
Thank you for your comment.
Author Response File: Author Response.docx
